window.onload = function() {

	var age = document.getElementById("age");
	age.oninput = function() {
		if (age.value < 0) {
			alert("您还没出生呢!");
		} else if (age.value > 99) {
			alert("您都快入土了!")
		}
	}
}


function equals() {
	var upwd1 = document.getElementById("upwd1").value;
	var upwd2 = document.getElementById("upwd2").value;
	var submit = document.getElementById("submit");
	if (upwd1 != upwd2) {
		submit.disabled = true;
	} else if (upwd1.length < 6 || upwd1.length > 16) {
		submit.disabled = true;
	} else {
		submit.disabled = false;
	}
}
